Mobile ad-hoc networks have become increasingly important in areas where deployment of communication infrastructure is difficult. A mobile ad-hoc network (MANET) is formed by multiple moving nodes equipped with wireless transceivers. The mobile nodes communicate with each other through multi-hop wireless links. Each node can transmit and receive information.
One type of MANET is a vehicular ad-hoc network (VANET) that refers to a mobile ad-hoc network designed to provide communications among nearby vehicles and between vehicles and nearby fixed equipment.
However, simply installing wireless antenna on a node and then transmitting uncoordinated communications would result in collision of data, interference between data and a significant transmission delay. By transmitting uncoordinated data, the airwaves would be flooded with a plurality of messages, which would result in a jamming of the radio waves, as the radio bandwidth is limited. As such, each node would interfere with each other's transmission and compete with each other for radio bandwidth for transmission. Further, all messages would propagate in all directions without any consideration of a desired transmission direction.
These problems become more apparent in ad-hoc networks where the nodes are moving at high speeds. The high mobility and lack of inherent relationships make a priori configuration of nodes into groups problematic. Information such as traffic advisories, Amber alerts, weather advisories, etc. must be relayed to all vehicles quickly, without delay and interference.
Additionally, information that is necessary for setting up safety communications must be exchanged in real-time, and vehicles in the groups must configure themselves in real-time so that safety communication can take place. The high mobility of uncoordinated vehicles implies frequent change of neighbors or vehicle groups, and poses difficulties of using support-servers (for mobility, address, name, media session) within vehicle groups. These key differences make existing tactical ad-hoc networking technologies not directly applicable to vehicle groups for safety communications.
Accordingly, there is a need for a method and system that allows for efficient relaying or broadcasting of message in a MANET or a VANET that can account for the mobility of the nodes and minimize interference and bandwidth usages.